Now that checkpoint IDs are deprecated (WT-14498), we should also remove all checkpoint_id arguments and functions from PALI and PALM.

This includes removing the following arguments:

• Remove the checkpoint_id argument from pl_begin_checkpoint, pl_complete_checkpoint, and pl_complete_checkpoint_ext.
• Remove the checkpoint_id argument from plh_get, plh_put, and plh_discard.
• Remove base_checkpoint_id and backlink_checkpoint_lsn from WT_PAGE_LOG_GET_ARGS, WT_PAGE_LOG_PUT_ARGS, and WT_PAGE_LOG_DISCARD_ARGS.

And updating the following functions (unless it is done as a part of WT-14591):

• Remove function pl_get_complete_checkpoint, and rename pl_complete_checkpoint_ext to pl_get_complete_checkpoint.
• Remove function pl_complete_checkpoint, and rename pl_complete_checkpoint_ext to pl_complete_checkpoint.
• Remove function pl_get_open_checkpoint.

Note that this would have to be done in conjunction with the server, as this changes function signatures and even function names.